Enhancement: Upload progress & overlay improvements

* Remove fetching of newly uploaded files and folders to improve performance
* Redesign the upload overlay
* Show uploading files in the upload overlay
* Immediately show the upload overlay when uploading folders to tell the user that the upload is starting
* Only show top level folders in the upload overlay when uploading folders
* Remove the Uppy StatusBar plugin
* Use `uppy.addFiles()` instead of calling `uppy.addFile()` for each file
* The upload overlay now shows a more proper time estimation when uploading many files
* The user feedback of the upload overlay during upload preparation has been improved
* Several router bugs have been fixed in the upload overlay
* Temporarily disabled `uploadDataDuringCreation` to prevent the local storage from getting to full
* Some more refactoring under the hood has been made

https://github.com/owncloud/web/pull/7067
https://github.com/owncloud/web/pull/7127
https://github.com/owncloud/web/issues/7066
https://github.com/owncloud/web/issues/7069
